ST. PAUL, Minn., Aug 31 -- Republican officials threw away the script for their presidential nominating convention on Sunday as Hurricane Gustav bore down on the Gulf Coast and threatened to cast a pall over a week intended to boost Sen. John McCain's campaign for the White House.

With Gustav expected to make landfall Monday morning, Republicans scrapped the bulk of their opening-day program, including a scheduled appearance by President Bush, and prepared for a much more sober week of events. McCain used the occasion to portray himself as above partisan politics.

The convention had originally been envisioned as McCain's chance to introduce his little-known running mate, Alaska Gov. Sarah Palin, and define Democratic nominee Barack Obama. But after flying to Jackson, Miss., to receive a briefing from Southern governors on hurricane preparations, McCain called on delegates to take off "our Republican hats and put on our American hats," as he put it in a televised briefing for reporters from St. Louis.

"We must redirect our efforts from the really celebratory event of the nomination of president and vice president of our party to acting as all Americans," McCain said in Jackson. "There's very little doubt that we have to go from a party event to a call to the nation for action -- action to help our fellow citizens in this time of tragedy and disaster, action in the form of volunteering, donations, reaching out our hands and our hearts and our wallets to the people who are under such great threat from this great natural disaster."

Convention organizers and McCain advisers watched nervously as Gustav chugged toward land, fearful that the storm could evoke memories of the administration's widely criticized response to Hurricane Katrina three years earlier as Republicans seek to rebrand a party that has been battered under Bush's leadership.

McCain campaign manager Rick Davis told reporters that the seven-hour program scheduled for Monday night will be pared down to a bare-bones session of roughly two hours, devoted mainly to meeting the legal requirements involved with opening the convention. He said that there will be no partisan speeches and that officials will assess what to do with the rest of the convention on a "day-to-day" basis until the magnitude of the storm damage becomes clear. He said the GOP will seek to make sure that "nothing we do detracts" from the response efforts in the Gulf states.

McCain's schedule is no less settled, although what is known centers on the crucial battleground states of Ohio and Pennsylvania. He spent Sunday night in Toledo and had planned to campaign in those states before arriving in St. Paul on Wednesday.

But the campaign is anxious not to appear celebratory when such tension grips the gulf states, and it is looking for ways for the candidates to show their concern. Both McCain and Palin retooled their speeches at a rally Sunday to talk about the responsibility of government when natural disasters strike.

Even war has not disrupted political conventions in recent years, but the extraordinary decision to alter what had been a meticulously planned coronation reflected the powerful and lingering political impact of Katrina. Although convention officials refused to discuss any political links between the Bush administration's response to Katrina and their current predicament, some Republicans here were clearly hopeful that by quickly shifting the theme of the convention to aiding relief efforts, they could buttress their efforts to show that a McCain administration would represent a departure from Bush. "It's beginning to creep around the edges that this could be a plus," said one GOP operative who listened in on a campaign conference call Sunday.

The White House canceled Monday night's convention speeches by Bush and Vice President Cheney and said the president would be flying to Texas to meet with evacuees and first responders. Bush, who was widely criticized for his initial response to Katrina, visited the Federal Emergency Management Agency's operations center to receive his own hurricane briefing even before Gustav made landfall.

Bush told reporters that he will not travel to Louisiana on Monday "because I do not want my visit to impede in any way the response of our emergency personnel." He said he spoke with governors and New Orleans Mayor C. Ray Nagin (D) over the weekend "to make sure that they're getting everything they need from the federal government to prepare for what all anticipate will be a difficult situation."

White House officials said that while Bush will not be going to Minnesota, he may address the convention by satellite video. They said that depends on events in the gulf.